# std::regex_traits<CharT>::length

From cppreference.com
< cpp‎ | regex‎ | regex traits

static std::size_t length( const char_type* p ); |  |

Calculates the length of a null-terminated character sequence, that is, the smallest `i` such that p[i] == 0.

Standard library specializations of std::regex_traits execute std::char_traits<CharT>::length(p);.

### Parameters

p | - | pointer to the first element of the null-terminated character sequence

### Return value

The length of the null-terminated character string.

### Example

Run this code

    #include <iostream>
    #include <regex>

    int main()
    {
        std::cout << std::regex_traits<char>::length("Кошка") << '\n'
                  << std::regex_traits<wchar_t>::length(L"Кошка") << '\n';
    }

Output:

    10
    5

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